From 53fd7544aff6d0a18869017cb9bb921a7f5dcd04 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Tue, 29 Jun 2021 11:24:38 +0200 Subject: [PATCH] match.pd: Avoid (intptr_t)x eq/ne CST to x eq/ne (typeof x) CST opt in GENERIC when sanitizing [PR101210] When we have (intptr_t) x == cst where x has REFERENCE_TYPE, this optimization creates x == cst out of it where cst has REFERENCE_TYPE. If it is done in GENERIC folding, it can results in ubsan failures where the INTEGER_CST with REFERENCE_TYPE is instrumented. Fixed by deferring it to GIMPLE folding in this case. 2021-06-29 Jakub Jelinek PR c++/101210 * match.pd ((intptr_t)x eq/ne CST to x eq/ne (typeof x) CST): Don't perform the optimization in GENERIC when sanitizing and x has a reference type. * g++.dg/ubsan/pr101210.C: New test. --- gcc/match.pd | 7 ++++++- gcc/testsuite/g++.dg/ubsan/pr101210.C | 13 +++++++++++++ 2 files changed, 19 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/ubsan/pr101210.C diff --git a/gcc/match.pd b/gcc/match.pd index 39fb57e..8205271 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -5124,7 +5124,12 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (cmp (convert @0) INTEGER_CST@1) (if (((POINTER_TYPE_P (TREE_TYPE (@0)) && !FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (@0))) - && INTEGRAL_TYPE_P (TREE_TYPE (@1))) + && INTEGRAL_TYPE_P (TREE_TYPE (@1)) + /* Don't perform this optimization in GENERIC if @0 has reference + type when sanitizing. See PR101210. */ + && !(GENERIC + && TREE_CODE (TREE_TYPE (@0)) == REFERENCE_TYPE + && (flag_sanitize & (SANITIZE_NULL | SANITIZE_ALIGNMENT)))) || (INTEGRAL_TYPE_P (TREE_TYPE (@0)) && POINTER_TYPE_P (TREE_TYPE (@1)) && !FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (@1))))) diff --git a/gcc/testsuite/g++.dg/ubsan/pr101210.C b/gcc/testsuite/g++.dg/ubsan/pr101210.C new file mode 100644 index 0000000..955b820 --- /dev/null +++ b/gcc/testsuite/g++.dg/ubsan/pr101210.C @@ -0,0 +1,13 @@ +// PR c++/101210 +// { dg-do run } +// { dg-options "-fsanitize=null,alignment -fno-sanitize-recover=null,alignment" } + +int v[2]; +int +main () +{ + int x; + int &y = x; + v[0] = reinterpret_cast<__INTPTR_TYPE__>(&y) == 0; + v[1] = reinterpret_cast<__INTPTR_TYPE__>(&y) == 1; +} -- 2.7.4